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June 13, 1933. J. ARMSTRONG TIMER Filed Jam 15, 1952- 2-Shaets-Sh eet 120 is Y www- INVENTOR Leonard/J. .5111? ATTORNEYS WITNESSES June 13,1933. J ARMSTRONG 1,914,231

' TIMER Filed Jan. 15, 1932 2 Sheets-Sheet 2 INVENTOR v WITNESSES vLeonard j lrmsfi'ongt j 6 M I Wkl. ATTORNEYS Patented June 13, 1933UNITED STATES PATENT omen v rnma Application filed January 15, 1888.jerlal No. 588,888.

An object of the invention is to provide a timer which is of articularvalue when used with internal combustion engines and which has positivemeans for moving a contact into and out of engagement with a stationarycontact to insure periodic contacts and to prevent missiing when theengine is running at high s so Another object of the invention is todispose an arm having the movable contact between two cams w ich engagethe arm and which positively move the arm back and forth as the cams arerotated, the movement of the arm not only being determined by the speedat which the cams rotate, but by the configuration of the cams.

Still another object of the invention is to maintain a predeterminedrate ofrotation of the cams relativel to each other.

The invention urther comprehends a timer in which a shaft is rovidedwith a cam and a gear, the gearmes. ing with a gear or ears on one ormore stub shafts, each of whic has a cam between which and the firstmentioned cam an arm of a movable contact is disposed to be positivelymoved back and forth relatively to a stationary contact or contacts withthe running of the engine.

Additional objects of the invention will appear in the followingspecification in which t e preferred form of the invention is de- In thedrawings similar reference characters refer to similar parts in theseveral views, of which Figure 1 is a plan view illustrating the timerwith parts broken away to show the construction,

Fi re 2 is a sectional view on the line 22 of Figure 1, and

Figure 3 is a plan view of a modified form of the invention.

By referring to the drawings, it will be seen that a hollow base 5 isrovided, the base having a bearing 6 in w ich is rotatably mounted ashaft 7. The hollow base 5 is closed b a plate 8 having an openingthrough which tile 5 aft 7 extends. Secured to this shaft 7, above the.plate 8, there is a gear 9 which meshes with gears 10 and 11, the gear10 being secured to a cam 12, the gear 10 and the cam 12 being mountedfor rotating on a stub shaft 13 which is secured to the plate 8 and to aframe 14. The gear 11 is secured to a cam 15, the gear 11 and the cam 15being mounted to rotate on a stub shaft 16 which is secured to the plate8. and to the frame 14, the frame 14 bein broken awa in Figure 1.Secured for rotating with the s aft 7 and the gear 9, there is' a cam17. It will be understood that, with the rotation of the shaft 7, thegear 9 and the cam 17 will be rotated and that through the gears 10 and11, which mesh with the ar 9, the cams 12 and 15 will also be rotated,ut in the op osite direction to the direction of rotation o the cam 17 I5 Disposed between the cams 17 and 15 there is an arm 18, which may be aspring arm, and which is anchored to a stud 19 mounted on' the late 8,the arm 18 having insulating mem' ers 20 at its sides which are engagedby the cams 15 and 17. In asimilar manner, an arm 21, which may be aspring arm, is dispeosed between the cams 12 and 17, the arm 21 inganchored to a stud 22 secured to the plate 8 and having insulatingmembers 23'at its'sides which are en ged by the cams 12 and 17 It willbe un erstood that the cams 12, 17 and 15 are of such a configurationthat, with their rotation by means of the shaft 7 and the ears 9 10 and11, the cams will en ga e the insulating members 20 and 23 at both si esof the arms 18 and 21 at all times, so that, with the rotation of thecams, the insulating members 20 and 23 at both sides of the arms 18 and21 will be ositively moved by the cams back and forth. Each of the arms18 and 21 is provided with oppositely disposed contact members 24 forengaging stationary contacts 25 between which the contact members 24-are disposed respectivel It will, therefore, be understood that, withthe rotation of the shaft and through the gears and cams which have beendescribed, the arms 18 and 21 will be positively moved back and forth,so that the contacts on the arms 18 and 21 will periodically en age thestationary contacts 25. Thesestationary contacts 25 are electricallyconnected with wires 26 leading from a primary circuit or circuits in aninduction coil or coils, the circuit being completed through thecontacts 24 and 25, the arms 18 and 21 and the ground at the studs 19and 22. The secondary circuit will preferably lead to a distributorbrush 27 mounted on a base 28 which is secured for rotating with theshaft 7 and which has an electrode 29 from which a spark may jum to acommunicating means leading to a spar plug.

It will be seen by referring to Figure 10f the drawings, that the arms18 and 21 are disposed at an angle to each other and that the cams 12,15 and 17 are so disposed that a contact on one of the arms is inengagement with one of the stationary contacts, while the contacts 24 onthe other arm are both spaced from the stationary contacts 25. It willbe understood that various arrangements may be made with reference topositioning the arms 18 and 21, and also that various arrangements maybe made with reference to the combination of the earns 12, 15 and 17, sothat any desired positioning of the contacts on one of the arms may beobtained relatively to the positioning of the contacts on the other armwhen the shaft has been turned to any predetermined position.

The construction illustrated in Figure 3 of the drawings corres ondswith the construction illustrated in igures 1 and 2 of the drawings,with the exception that the stationmy contacts 25 are insulated fromeach other and that there are preferably four coils, a primary circuitin each coil being connected by the wires 30, 31, 32 and 33 with each ofthe stationary contacts 25'. It will also be seen that in Figure 3 ofthe drawin the arms 18 and 21' are disposed paralle with each other,while in Figure 1 of the drawings the arms 18' and 21' are dis at anangle to each other. It will also be seen that in Figure 3, the frame14' has arms 34 which are mounted on the studs 19' and 22', the saidstuds 19 and 22' being disposed at opposite sides of the plate 8. Theframe 14' is preferably insulated from the stub shafts 13 and 16.

What is claimed is:

1. In a timer, two rotatable cams, an arm having a movable contact, thearm being disposed between the cams, the cams havin cam surfaces whichengage opposite sides 0 the arm at all times to positively move thetacts.

arm back and forth, and a stationary contact or contacts for engagementby the movable contact.

2. In a timer, two rotatable cams, an am having a movable contact, thearm being disposed between the cams, the cams having cam surfaces whichengage opposite sides of the arm at all times to positively move the armback and forth, a stationary contact or contacts for engagement by themovable contact, and eari connecting the cams.

3. a timer, two came, a shaft for rotating one of the cams, gearingconnecting the cams for rotating the other cam a movable contact havingan arm disposed between the cams to be operated thereb and twostationary contacts between which the movable contact is disposed forperiodically engaging the stationary contacts.

4. In a timer, a shaft having a gear, a cam secured to the shaft, twostub shafts, two additional gears meshing with the first mentioned gearand with one mounted on each stub shaft, two additional cams, onesecured for rotating with each of the additional gears, two arms, eachdisposed between one of the additional cams and the first men tioned camto be positively moved back and forth thereby, two movable contacts, onemounted on each of the arms, and a plurality of stationary contactspositioned for engage ment by the movable contacts.

5. In a timer, a shaft having a car, a cam secured to the shaft, twostub s afts, two additional gears meshing with the first mentioned gearand with one mounted on each stub shaft, two additional cams, onesecured for rotating with each of the additional gears,

two arms, each dis between one of the additional cams an the firstmentioned cam to be positively moved back and forth thereby, the armshaving insulation at the cams, two movable contacts, one mounted on eachof the arms, and a plurality of stationary contacts positioned forengagement by the movable contacts.

6. In a timer, a shaft having a gear, a cam mcured to the shaft, the camhaving a plurality of cam surfaces,- two stub shafts, two additionalgears, one mounted for rotating on each stub shaft, the additional gearsmeshing with the first mentioned gear, two additional cams, one securedfor rotatin with each additional gear, each of the additional camshaving a plurality of cam surfaces corresponding in number with the camsurfaces of the first mentioned cam, two arms, each disposed between oneof the additional cams and the first mentioned cam to be positivelymoved back and forth thereby, the arms having insulation at the cams,two movable contacts, one mounted on each of the arms, and a pluralityof stationary contacts positioned for engagement by the movable con- 7.In a timer, two 0 an movable contact, the arm being disposed tween thecams to be positively moved back and forth thereby, a stationary contactor contacts for engagement b the movable contact, and means to rotate ecams in unison.

8. In a timer, a cam, two additional cams, two arms extending at anangle to each other, each arm being disposed between the first mentionedcam and one of the said additional cams to be operated thereby, contactson each of the arms, and two sets of contacts, each set armhavin a ofcontacts being positioned for engagement by the contact or contacts onone of the arms. 9. In a timer, a cam, two additional cams, two armsextending at 'anangle to each other, each arm being disposed between thefirst mentioned cam and one of the said additional cams to be operatedthereby, contacts on each of the arms, two'sets of contacts, each set ofcontacts being positioned for engagement by the contact or' contacts onone of the arms, and means for rotatin the cams. 10. In a timer, a cam,two additional cams, two arms each dis osed between the first mentionedcam an one of the additional cams, two pairs of contacts, a contact orcontacts on each arm disposed between a pair of the first mentionedcontacts, and means to rotate the cams.

11. In a timer, t'wo cams, an arm havin a movable contact, the arm beingdi osed tween the cams and being engage by the two cams at all times, astationary contact or contacts for engagement by, the movable contacts,and means to move the cams relatively to each other.-

LEONARD J. ARMSTRONG.

